I have both and I find the shag super, super plush and soft and sucks moisture right up. The microfiber feels a lot more rigid to me somehow and I can hear the crinkly middle absorbent portion more too.

I only have the microfiber, but from what I have read, the shag is somewhat more absorbent because of the thicker "furry" material. However, either will do the job of protecting your bed from fluids. I love my microfiber throe!

I like the Shag Liberator Throe. It is really thick and also larger than the other Throe.

I hope people realized that the OP was talking about Liberator Throes and not just the fabric. (At least I think the OP was talking about Liberator Throes. And, yes, that's how Liberator spells "Throe.") I'm sitting on mine right now.